David Sinclair: what the most argued-about man in longevity science actually takes

If you have spent any time reading about healthy ageing, you have come across David Sinclair. The Harvard geneticist wrote the bestseller Lifespan, runs a leading ageing research laboratory, and did more than anyone to bring NMN and resveratrol into the public conversation. He is also one of the most criticised figures in longevity science.

This post covers both sides. First, the criticism, then his personal routine, because there is a difference between what someone sells and what they do, and the personal choices of someone who has spent thirty years inside this research are interesting in their own right.

Why scientists keep criticising him

The criticism goes back a long way. In 2008, a company Sinclair co-founded, Sirtris Pharmaceuticals, was bought by GlaxoSmithKline for US$720 million on the promise of resveratrol-based medicines. GSK later wound the programme down without bringing a drug to market, and many researchers concluded that the early enthusiasm had run well ahead of the evidence.

Then there is the NMN episode, which some of you may remember directly. In late 2022, the US FDA determined that NMN could no longer be sold as a dietary supplement in America. The trigger was a drug application from Metro International Biotech, a pharmaceutical company Sinclair co-founded, which is developing a pharmaceutical form of NMN. Under US law, an ingredient under investigation as a new drug can be excluded from the supplement market, and a year later Metro wrote to the FDA urging it to keep that exclusion in place. The reaction in the longevity community was furious, with many accusing Sinclair of helping restrict public access to the very compound he had popularised. Sinclair pushed back, saying he has never been involved in any company selling NAD boosters as supplements, and that bringing NMN through the approval process as a medicine was in the public’s interest. After industry lawsuits, the FDA reversed its position in late 2025, and NMN is legal in US supplements again. None of it ever affected availability here in New Zealand. And whatever else the episode showed, a company spending years trying to turn NMN into a prescription medicine is not a company that doubts the molecule.

The most recent episode is sharper still. In early 2024, Animal Biosciences, a company Sinclair co-founded and his brother runs, issued a press release quoting him saying their supplement was “proven to reverse ageing” in dogs. Fellow researchers objected immediately. Matt Kaeberlein, one of the most respected scientists in dog ageing research, publicly called the statement a lie and resigned his membership of the Academy for Health and Lifespan Research in protest. The company corrected the wording, and Sinclair stepped down as the Academy’s president.

Running through all of it is the same underlying concern: Sinclair holds commercial interests in a number of longevity companies, and critics argue this makes his public enthusiasm hard to take at face value.

None of this makes his laboratory research wrong. His published science goes through the same peer review as anyone else’s. The criticism is about his public claims, which have repeatedly outrun what the studies show.

So why pay attention to him at all?

Because what he takes tells you something different from what he says. Sinclair’s personal routine represents where a genuine insider, with full knowledge of the research and its limitations, is placing his own bets. He has also been consistent on one point that almost nobody in the field disputes: the everyday foundations of diet, exercise and sleep matter more than any capsule.

He describes his routine as personal, not a recommendation. With that understood, here is what he has said publicly that he takes, and where the evidence sits for each.

His routine, item by item

NMN. Sinclair has long said he takes around 1 gram of NMN each morning. NMN is a precursor to NAD+, a coenzyme involved in cellular energy production and DNA repair, and NAD+ levels decline as we age. Human trials so far are early but genuinely interesting: studies have reported improved muscle insulin sensitivity in prediabetic women (study, Science, 2021), improved walking distance in middle-aged and older adults (study, GeroScience, 2023), and effects on muscle function in older men (study, npj Aging, 2022). Whether raising NAD+ translates into meaningful long-term healthy ageing outcomes is still an open question that researchers are actively working on.

Trans-resveratrol. He has said he takes about 1 gram of resveratrol daily, mixed with yoghurt because it absorbs better with fat. This is the compound at the centre of the Sirtris story. Laboratory studies show resveratrol can activate sirtuins, proteins involved in cellular stress responses and metabolism. Human trials have been mixed, with some showing effects on markers like blood sugar regulation and others showing little. A recent randomised controlled trial published in the European Journal of Nutrition (study, 2025) is among the more encouraging, but the field is far from settled. See our latest Trans Resveratrol article here.

Spermidine. Sinclair takes spermidine, a compound found in wheat germ, mushrooms and aged cheese, which researchers are studying for its role in autophagy, the cellular recycling process. The evidence here is a good example of why we hedge. Population studies have linked higher dietary spermidine with lower mortality (study, American Journal of Clinical Nutrition, 2018), and an early pilot in older adults suggested memory benefits, but a larger follow-up trial at a low dose found no significant effect on cognition (study, JAMA Network Open, 2022). Promising biology, unfinished evidence. 

Glycine. An amino acid involved in collagen production and the body’s synthesis of glutathione, its master antioxidant. Glycine is one half of the GlyNAC combination, which showed encouraging results on multiple ageing markers in a small randomised trial in older adults (study, 2022), though the sample was small and more research is needed.

TMG. Sinclair has said he takes TMG (trimethylglycine) to support methylation, since NAD+ precursors consume methyl groups as they are processed. The rationale is biochemically sensible, though direct trial evidence for pairing the two is limited at this stage – see article here.

Vitamin D and vitamin K. Two well-established nutrients with recognised roles in bone health and normal physiological function. The least controversial items on his list.

Nattokinase and niacin. Sinclair has said he takes nattokinase, an enzyme from fermented soybeans being studied for cardiovascular health, and niacin (vitamin B3), which he attributes to his own cardiovascular risk profile. He has been clear these reflect his individual health circumstances. He has also mentioned prescription medicines as part of his medically supervised healthcare. Those are personal medical decisions between him and his doctors, and we will leave them there.

The part nobody argues with

For all the controversy around his supplement claims, Sinclair’s foundations are conventional and well supported. He eats a largely plant-based diet built around vegetables, legumes and nuts. He keeps his eating within a restricted daily window. He exercises regularly, limits alcohol, and prioritises sleep. Exercise in particular remains the single most evidence-supported thing anyone can do for healthy ageing, supporting cardiovascular fitness, muscle strength and metabolic health at every age.

If you took nothing else from his routine, this section would be the part to take.

What this means for you

A few practical points from all of this.

Start with the foundations. Movement, a plant-rich diet, sleep and stress management have stronger evidence behind them than any single compound, and they cost very little.

If you are curious about the compounds he takes, understand where each one sits on the evidence ladder. Some, like NMN, have early human trials. Others, like spermidine, have promising biology and mixed trial results. A distinction that matters when you decide where to spend your money.

His doses are his, not a template. Sinclair takes amounts that reflect his own reading of the research and his own health circumstances, with medical supervision. Talk to your GP or a qualified health professional before adding anything new to your routine, especially if you take medication.

And weigh the messenger alongside the message. Sinclair has commercial interests and a record of overstating results. That does not make everything he says wrong, but it is a good reason to check claims against the published research, which is what we try to do in these posts.

Several of the compounds in his routine, including NMN, trans-resveratrol, TMG, GlyNAC, spermidine and Vitamins D, K and B3, are ones we formulate and encapsulate here in New Zealand. If you want to dig further into the research on any of them, the articles linked above are a good place to start, and if you have questions, reply to any of our emails. A real person reads them.

Stephen at MyVitality

This article is for general information only and is not medical advice. Supplements can interact with medicines and are not suitable for everyone. Always speak with your doctor or a qualified health professional before making changes to your supplement routine.